In recent years, genetic tests have rapidly prevailed in the field of clinical diagnoses. A genetic test is a test that examines, for clinical purposes, whether there is a mutation or karyotype that is relevant to a genetic disease by analyzing nucleic acids or chromosomes. Examples of a genetic test include a test that determines whether there is a nucleic acid derived from cancer cells in a tissue sample resected from an organism. The test process includes three major process steps of preprocessing, nucleic acid amplification, and detection.
In the preprocessing, a crushing process to crush (homogenize) a tissue sample is performed. As one method of this crushing process, there is widely used a crushing method in which a crushing tool called a blender is brought, while being rotated, into contact with a tissue sample. U.S. Pat. No. 8,216,528 discloses a sample processing device which crushes a tissue sample by the above crushing method. The sample processing device disclosed in U.S. Pat. No. 8,216,528 includes a crushing tool composed of an inner crushing member and an outer side crushing member which is a tubular body capable of housing the inner crushing member therein. The sample processing device is configured such that a tissue sample (lymph node) is crushed to a predetermined size, by the inner crushing member of the crushing tool being repeatedly moved upward and downward while being rotated by a motor.
In the sample processing device disclosed in U.S. Pat. No. 8,216,528, when the crushing tool is moved downward, the tip of the crushing tool is pressed against a tissue sample, and in this state, the inner crushing member of the crushing tool is rotated, whereby the tissue sample is crushed. Here, it is known that a cancerous lymph node is harder than a non-cancerous lymph node. When crushing a hard lymph node, if the inner crushing member of the crushing tool is pressed with an excessive force, there may be a case where the inner crushing member bites into the lymph node to get stuck therein and becomes unable to rotate. This may result in a crushing failure of the tissue sample of the lymph node.